[time-nuts] Lucent KS-24361, HP/Symmetricom Z3809A, Z3810A, Z3811A, Z3812...
GandalfG8 at aol.com
GandalfG8 at aol.com
Sun Nov 2 02:34:44 EST 2014
Oh well, as was said before, one of the biggest problems working on
something like this can be the watching and the waiting, but sometimes it might
be worth the wait, and sometimes having a bit of luck thrown in along the
way can be quite handy too:-)
As mentioned earlier, I'd implemented Arthur's circuit but left the fault
light connection as a flying lead to be switched manually.
Originally, after the unit started up with the fault light on, I found
that when the light eventually went out I had to switch this input to ground
to enable the outputs.
As a follow up though it did seem worth trying with this connection
grounded all along, just out of curiosity of course, and it also seemed to start
up just fine like that:-)
A quick look at the circuit showed that this left the wire to J5 pin 3 also
grounded all along and a question hanging over what was happening to J5
pin 4.
In the static condition there's approx 1.5 volts across the 470 ohm
resistor but it would normally get pulsed at some time in the proceedings.
However, with the fault light connection permanently grounded it didn't look like
this was going to be exactly hyper active either.
So the next step was to directly ground J5 pin 3 and for J5 pin 4 to be
grounded via the 470 ohm resistor, without knowing what was driving it from
inside the unit a direct short could have been asking for trouble, and to
dispense with the transistor circuit.
And guess what, that worked too:-)
So it would seem that whilst all the blinking of lights and assorted
handshaking and negotiating are necessary to sort out the status quo between two
boxes, it might be a bit less complicated with just the one after all.
By way of confirmation I wired up another Ref-1 unit, straight out of the
box and previously unused, powered it up, and left it to get on with it.
After the quick LED test sequence it started out with the "No GPS" and
"Fault" lights on permanently and the "STBY" and "ON" lights off.
Just about 75 minutes later the "No GPS" and "Fault" lights went out, the
"ON" light came on permanently, and we had 15MHz and 1PPS outputs from
that one too:-)
One as yet unexplained difference between the two units is that the first
one performed in a similar fashion but the "ON" light was flashing from
shortly after the initial test sequence, even whilst the "No GPS" and "Fault"
lights were still on, and it remained flashing after they went out, and so
far has never been on permanently at all.
I've since put that one back on test and it's still behaving in the same
way but still booting up ok just the same.
Whether this indicates some sort of fault condition in the first unit,
running just the bare board might have been asking for trouble, or some form
of randomness in behaviour such that these results aren't entirely
predictable, I don't know, but so far both seem to be consistent in their own
fashion and two out of two isn't a bad start:-)
It would be appreciated if others could try this too, confirmation that it
works elsewhere would be great, and knowing it was a pure fluke and never
to be repeated could be quite useful too:-)
To recap, this is a Ref-1 unit with onboard GPS and what I'm doing is to
make the following connections to the J5 "Interface" connector, using a
small plug in breadboard as a temporary junction box.....
Pins 2, 10, 12, and 15 of J5 are connected together but not connected to
anywhere else.
Using a ground connection taken from J5 pin 8, J5 pin 3 is connected
directly to ground, and J5 pin 4 is connected to ground via a 470ohm resistor,
again with no other connections.
That's it, after power up and an appropriate delay, assuming my results are
repeatable, the outputs should be enabled and away we go.
Uh oh, after writing the above it occurred to me as an afterthought that I
should probably also check what might happen if J5 pin 4 was disconnected
altogether, so I removed the 470ohm resistor from the original unit whilst
it was running and the voltage on pin 4 rose to just over 4.7 volts, the
"ON" light continued to flash.....
and the outputs remained enabled.
After that I just have to try it from start up, and also to try it on the
second unit too, who needs sleep anyway?:-)
The first one did start up ok with J5 pin 4 disconnected and whilst
waiting for that to come live I've made up a plug adapter using an old VGA patch
cable and now have the second one on test again and waiting to see what
happens this time.
And there you have it, finally, the other one up and running again also:-)
I happened to be watching this one this time as it went live and the "ON"
light flashed once before coming on permanently, perhaps not very
significant but just thought I'd mention it anyway.
So that's it folks, after all this it would now seem that all that's
needed to enable a Ref-1 unit stand alone is to link together J5 pins 2, 10, 12,
and 15, and to ground pin 3 to pin 8, and then just hang around for hours
and hours on end with yer fingers crossed:-)
I don't know if it's possible to monitor the J8 Diagnostic port whilst
waiting for it come live, that would at least give a better idea of what's
going on, but I deliberately avoided any other connections whilst trying this
out so it's possible that might be inhibited also.
Anyway, apologies for all the waffle, I've been topping this up as I go
along whilst surviving on coffee and getting a bit groggy in the process,
it's 0730 here now and no sleep yet, but once I'd had my first encouraging
results there was no way I could just go to bed and leave it:-)
Regards
Nigel
GM8PZR
In a message dated 02/11/2014 02:00:23 GMT Standard Time, kb8tq at n1k.org
writes:
Hi
I’ve watched the two boxes fire up. They spend a bit of time blinking
lights on this one and then on that one. From watching the “dance”, I think
that the transistor delay circuit (or something like it) is indeed needed.
There are multiple ways the delay and sequencing could be implemented. A
cheap 5V PIC is certainly one way to do it. With no voltage coming out on the
connector doing a purely external solution probably is going to require
external power. I think I’d at least bring that out on one of the many unused
alarm pins.
Bob
> On Nov 1, 2014, at 9:52 PM, GandalfG8--- via time-nuts
<time-nuts at febo.com> wrote:
>
> Hi Bob,
>
> I understand the consequences of not modifying the unit but, having done
so
> and having a REF-1 unit running stand alone, I was just commenting that
I
> wasn't sure whether or not it was necessary to implement all of
Arthur's
> modification in order to enable the basic functionality, or whether some
> part of it might be purely to control the indicators.
>
> As a follow on from that I was wondering whether or not it might be
> possible to achieve a similar result, at least to the point of just
making it
> functional, just by cross linking some of the out and return paths,
"faking"
> it without the need for an additional powered interface if you like,
not for
> any other reason than it might then be possible to make a plug in
> modification that could be fitted without needing to open the box.
>
> Regards
>
> Nigel
> GM8PZR
>
>
>
>
> In a message dated 02/11/2014 00:19:57 GMT Standard Time, kb8tq at n1k.org
> writes:
>
> Hi
>
> If you:
>
> 1) Do not have two units (Ref 0 and Ref 1)
>
> — and —
>
> 2) Do not “fake out” the slave detect (= use the mod)
>
> Then the unit you have will not:
>
> 1) Enable the pps out
>
> 2) Enable the 15 MHz out
>
> It will try to disciple the OCXO, but you won’t be able to see any
result
> of that.
>
> Bob
>
>
>> On Nov 1, 2014, at 7:05 PM, GandalfG8--- via time-nuts
> <time-nuts at febo.com> wrote:
>>
>> Hi Anthony,
>>
>> It's a new circuit that has to be inserted, which is what I've done,
but
>
>> I'm not sure whether or not it's strictly necessary for the unit to
> function
>> or whether it's just there to get the lights sequencing properly and
>> perhaps all that's needed for basic functionality are just the links.
>>
>> I'm leaving well alone for now to let the oscillator run overnight but
>> will try it again tomorrow with just the links and see what happens.
>> I'm also hoping to get some idea of the between unit signalling,
> although
>> I only have Z3811s I'm hoping, with the boards being an almost
> identical
>> match, that what goes one way should be matched by what comes the
other.
>>
>> Regards
>>
>> Nigel
>> GM8PZR
>>
>>
>>
>> In a message dated 01/11/2014 22:41:09 GMT Standard Time,
> aroby at antamy.com
>> writes:
>>
>> I wasn't clear from the photo whether the circuit was a
representation
> of
>> what is on the board, and you just had to connect the pins listed
> together,
>> or whether this was a new circuit that had to be inserted. Sounds
like
>> the latter?
>>
>> Anthony
>>
>> -----Original Message-----
>> From: time-nuts [mailto:time-nuts-bounces at febo.com] On Behalf Of
>> GandalfG8--- via time-nuts
>> Sent: Saturday, November 01, 2014 4:04 PM
>> To: time-nuts at febo.com
>> Subject: Re: [time-nuts] Lucent KS-24361, HP/Symmetricom Z3809A,
> Z3810A,
>> Z3811A, Z3812...
>>
>> Well, I'm happy to report that Arthur's modification does do the
trick,
>> although I don't know why as I don't have any data for the interface
> as yet.
>> I daren't disturb the 15 pin connector right now as this Z3811A PCB
is
>
>> still out of its case and connected to a breadboard with wires just
> pushed
>> into the sockets, and for the same reason I don't have any computer
>> connection at the moment either.
>>
>> My implementation isn't quite as described, in that I've not made a
>> connection to the fault LED but am just manually pulling that input
> high and low
>> on the breadboard with another wire link as required.
>> Whether or not this is part or all of the reason that my green "on"
> light
>> is flashing rather than steady I don't know, but I am seeing the 1PPS
> and
>> 15MHz outputs and the 15MHz looks to be conditioning ok.
>>
>> Aside from the 5 volt supply, which I'm picking off from pin 5 of the
>> header between u33 and U34, and the aforementioned fault LED
> connection, all
>> the other connections can be made to J5 externally and could be
housed
> in a
>> 15 way shell along with the switching circuits.
>>
>> I'm still hopeful that some cross linking of the right pairs might
>> achieve the same result without the extra circuitry, so "all" that
> needs to be
>> done now is just to identify the right pairs:-)
>>
>> At least with it up and running it should be easier to check out some
> of
>> the inter-unit signalling.
>>
>> Thanks Arthur, your efforts are much appreciated.
>>
>> regards
>>
>> Nigel
>> GM8PZR
>>
>>
>>
>>
>>
>>
>>
>> In a message dated 01/11/2014 15:25:02 GMT Standard Time,
> aroby at antamy.com
>> writes:
>>
>> For those who missed it, Arthur's post is at
>> https://www.febo.com/pipermail/time-nuts/2010-June/047825.html and
the
> photo is at
>>
>
http://i906.photobucket.com/albums/ac262/rjb1998/RFTG-uREF1photo1_zps87c505ca.jpg
>>
>> Anthony
>>
>>
>>
>>
>> -----Original Message-----
>> From: time-nuts [mailto:time-nuts-bounces at febo.com] On Behalf Of
> Arthur
>> Dent
>> Sent: Friday, October 31, 2014 9:20 PM
>> To: time-nuts at febo.com
>> Subject: [time-nuts] Lucent KS-24361, HP/Symmetricom Z3809A,
Z3810A,
>> Z3811A, Z3812A GPSDO system
>>
>> Bob Stewart bob at evoria.net
>> ?? ? I have both of my units sitting on the bench. I found that I
> needed
>> to connect them together to get the REF1 unit to come out of standby
?
> . ??
>>
>> Bob Camp kb8tq at n1k.org
>> ??I suspect that somebody will have to figure out what the 15 pin
>> connector / jumper is doing. On previous RFTG units there was a way
to
> re-wire
>> the crossover interface to fake out the slave detect process. That
> would let
>> you run a single GPS equipped box and have it behave correctly.
> Without
>> the fake wires trick none of them played nice without the slave
being
>> present ?
>> . ??
>> ++++++++++++++++++++++++++++++++++++++
>> Reposting what I had posted over a week ago, in case you missed it ?
.
>>
>> Arthur Dent golgarfrincham at gmail.com Wed Oct 22 13:59:48 EDT 2014
> ??
>> ?
>> Way back on Fri Jun 11 16:48:43 UTC 2010 I posted about using one of
>> these units I had modified but at the time there wasn't a single
person
> who
>> was interested. I have been using the RFTG-u REF1 since then and it
is
> a
>> nice unit. The modifications I added (including a power supply -see
> photo)
>> allows the lights to cycle through their normal sequence on warm-up
> and the
>> second unit isn't needed at all ? . ??
>>
>> -Arthur
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